When authoritarians are in power long enough, whatever ideology the revolution the previous generation had gets replaced by an emphasis of simply maintaining power through whatever means necessary. And fascism is the easiest way to accomplish that.

We can debate over whether Mao was really socialist or whatever, but he's dead it doesn't much matter now. The CCP today is accepting of billionaires, capitalism is legal, labour unions are illegal, the leadership is misogynistic, oppressive towards minorities, promotes the "century of humiliation" narrative. Oh and people live in fear of another Tienanmen Square style massacre. Whatever China was in the past, it's fascist today.

And Russia? WTF are leftist (or so they claim) weirdos going on about there? The Soviet Union collapsed and was replaced with a capitalist democracy which became fascist under Putin's regime.

There's this weird thing where so-called leftists think that if some kind of socialism existed on a patch of earth then they need to carry water whatever fascist that's ruling over that patch of earth today.